The present invention relates to gas seals, and in particular to a gas seal for aerospace engines and other similar applications.
Gas seals are generally well known in the art, and are used in conjunction with a wide variety of turbo machinery, such as jet engines, turbines, compressors and the like, to form a non-liquid or gas seal between two portions of an associated turbo machine. Examples of such gas seals are disclosed in U.S. Pat. Nos. 3,640,541; 5,066,026; 5,174,584 and 6,142,728. In general, such gas seals include a rotating metal seal plate that is attached to an associated rotating drive shaft, which incorporates an annular face that seals against the annular face of an associated stationary face seal or ring that is typically made of carbon or the like and mounted in an associated stationary housing. A biasing mechanism, such as springs or the like, is typically provided to urge adjacent faces of the carbon ring seal and the seal plate together. Furthermore, in non-contacting or lift off gas seals, the interior or sealing face of the carbon ring seal is typically provided with a series of very small grooves which form gas ramps that hydrodynamically create a thin gas film between the adjacent faces of the carbon ring seal and the seal plate, such that the same lift off of one another and do not actually come into contact when the gas seal is in full operation.
Gas seals for aerospace engines must be extremely lightweight, compact, capable of withstanding very high pressures and temperatures, and very durable even at extremely high speeds in excess of 26,000 rpm. A gas seal which can meet the exacting dimensional, weight, stress and thermal demands experienced in high speed aircraft gas turbine engines would be clearly advantageous.